The detergency art continues to evolve, particularly with the advent of new types of fabric, and consequently, new types of fabric cleaning and/or conditioning products. The detergency art has experienced similar expansion in the area of dishwashing, whether automatic or manual. Indeed, there exists a plethora of fabric and dish cleaning and/or conditioning products in the marketplace, each of which purports to achieve a different objective. Those skilled in detergency art have generally relied on the duplication of typical fabric and dish cleaning and/or conditioning environments in which to develop and analyze new fabric and dish cleaning and/or conditioning products. The duplication of these environments has certainly proven to be useful, as evidenced by the successful development of many, new fabric and dish cleaning and/or conditioning products. Nevertheless, the duplication of cleaning and/or conditioning environments is dependent upon the accurate identification and replication of the typical manners in which consumers clean and/or condition their fabric articles and dishes. Consumers oftentimes have difficulty in keeping accurate and complete records of their habits and practices. As a result, those skilled in the detergency art must often conduct surveys and lengthy investigations to ascertain the mode in which consumers typically employ fabric and dish cleaning and/or conditioning products.
In an effort to more accurately identify the properties of the environments in which consumers tend to clean and/or condition fabric and dishes, those skilled in the art have sought to develop monitoring devices that may be placed directly into a fabric and dish cleaning and/or conditioning environment, including that of a consumer and/or a laboratory testing facility. Skilled artisans have rigorously attempted to resolve this dilemma, as evidenced by the development of a few such devices in the recent past. Unfortunately, the development of these devices has had the general affect of complicating, rather than simplifying, the efforts to monitor particular environments. These complications are due largely in part to the fact that current monitoring devices are capable of measuring only one chemical and/or physical parameter. Thus, in order to measure several, chemical and/or physical parameters, practitioners must deploy a multitude of devices.
One prior art attempt at a monitoring device is described in PCT Publication No. WO 01/07702. The monitoring device described and illustrated in this reference is not without shortcomings. The device is described and illustrated as requiring a “sample reservoir” in which an aliquot of a wash fluid is captured and measured. The device is designed such that the capturing of an aliquot into the sample reservoir is easier than the evacuation of such aliquot from the sample reservoir due to the “funnel-shaped channel” which leads to the sample reservoir. As a result of this sample reservoir, this device can only measure parameters when, and if, a sample of wash liquid is present in the sample reservoir. Thus, this device is not capable of providing “real-time” measurement of parameters within the wash fluid because there is a delay between getting fluid into the sample reservoir and measuring the parameters once the fluid is present in the reservoir. In other words, the measuring means of this device are not in constant contact with the entire volume of the liquid continuously, but rather just a time-specific sample thereof. Further, once a sample is present in the sample reservoir, it is difficult, if not impossible, to remove all of the measured sample to ensure that the reservoir is clean before a next sample to be measured enters the reservoir. In light of the foregoing, it is clear that this prior art device is not capable of providing accurate measurements of a fluid, which is in a state of flux with regard to its conditions.
Accordingly, there is a need for a sensor device that is capable of continuously detecting, identifying and/or measuring a chemical and/or physical characteristic of an environment, especially a liquid medium, and most especially in the research into, and operation of, automatic laundering and dishwashing machines, especially under real life conditions.